Philip Pullman, the Whitbread award-winning author of His Dark Materials, has condemned children's television as 'social poison', treating its audience as marketing opportunities while portraying them as dangerous and feral.

Pullman castigated broadcasters for sacrificing high-quality programmes in favour of those that yield more marketing opportunities. 'Children are regarded by broadcasters as a marketing opportunity at best, a dangerous and feral threat at worst, and an expensive nuisance otherwise,' Pullman said. 'This social poison goes much deeper than broadcasting, of course, but it's particularly visible there.

'There used to be ... a sense of responsibility among broadcasters: a feeling that this extraordinary medium ... should be used to make things better, richer, more interesting for those who made up the audience - especially for children,' he added.

There are now more than 20 dedicated pay and free-to-air children's channels, but spending on original children's programmes on public service channels has declined in real terms by more than a third, while the average cost of producing one hour of original children's programming fell from £85,000 in 1998 to £57,000 in 2006. ITV responded to this shifting market recently by announcing it would not commission any new children's programmes, a decision that caused Ofcom to launch a review of children's programming, the results of which will be published later this year.

But Pullman is concerned the damage done to children's television has gone too far to be corrected without more effort. 'The ideology of "profit before everything" in children's television is toxic,' he said. 'When young audiences are regarded as customers to be separated from their money as quickly and efficiently as possible, there is no chance for life-enhancing work to flourish.'

Much of Pullman's own work has appeared on television, with the author's blessing. When Billie Piper and Julie Walters were confirmed as protagonists in the BBC production of his novel, The Ruby in the Smoke, he said he was delighted, because he had 'always felt that TV, rather than film, was the natural home for the Sally stories'.

Pullman went on to say that fiction loses its value unless it 'tackles the great moral dilemmas of our time'. 'Fantasy, and fiction in general, is failing to do what it might be doing,' he said. 'It has unlimited potential to explore all sorts of metaphysical and moral questions, but it is not doing that.

'You can't leave morality out unless your work is so stupid and trivial and so worthless that nobody would want to read it anyway.

'Taking children's needs seriously is not different from taking every human need seriously,' he said. 'It is absolutely central to a true and humane vision of the whole of life. If we need to challenge the prevailing neo-liberal, market-based religion in order to do it, then we should do so proudly.'

Pullman's new film, The Golden Compass, starring Daniel Craig and Nicole Kidman, the first of three to be based on the trilogy, His Dark Materials, opens on 7 December.